Q:
I quote from http://chandra.harvard.edu/photo/2000/0170/index.html:
"The Roman numerals refer to how many electrons have been
stripped from the atoms. e.g. OVIII is an ion that has lost 7
electrons from its atomic shell, NeX has lost 9 electrons, etc."
This does not make sense. Do you mean OVIII has lost eight
electrons and NeX has lost ten?

A:
Blame it on the Romans for not inventing zero. The neutral
atoms, with zero electrons removed are labeled with I. For
example HI for a neutral hydrogen atom, OI for a neutral oxygen
atom, etc.